Solved Problem 5-1 Demand for patient surgery at Washington General Hospital has increased steadily in the past few years, as seen in the following table:
YEAR | OUTPATIENT SURGERIES PERFORMED |
---|---|
1 | 45 |
2 | 50 |
3 | 52 |
4 | 56 |
5 | 58 |
6 | — |
The director of medical services predicted 6 years ago that demand in year 1 would be 42 surgeries. Using exponential smoothing with a weight of
YEAR | ACTUAL | FORECAST (SMOOTHED) | ERROR | |ERROR| |
---|---|---|---|---|
1 | 45 | 42 | 3 | |
2 | 50 | 7.4 | ||
3 | 52 | 7.9 | ||
4 | 56 | 10.3 | ||
5 | 58 | 10.3 | ||
6 | — | — | — | |
38.9 |
Solved Problem 5-2 Quarterly demand for the Jaguar XJ8 at a New York auto dealership is forecast with the equation
where
and
The demand for luxury sedans is seasonal, and the indices for quarters 1, 2, 3, and 4 are 0.80, 1.00, 1.30, and 0.90, respectively. Using the trend equation, forecast the demand for each quarter of next year. Then adjust each forecast for seasonal (quarterly) variations.
Quarter 2 of this year is coded